Small sized integrated camera devices, like those for mobile phones, are susceptible to interference due to electromagnetic wave interactions.
Electromagnetic compatibility (EMC) of electronic components is becoming increasingly important. Electromagnetic compatibility (EMC) refers to the ability of an electrical device to work satisfactorily in its electromagnetic environment without adversely either influencing the surrounding devices, or being influenced by them. Electromagnetic shielding limits the flow of electromagnetic fields between two locations, by separating them with a barrier made of conductive material.
Typically, a conductive barrier is applied to an enclosure to function as a EMC shield. Shielding can reduce the coupling of electromagnetic fields. The amount of reduction depends upon the material used, its thickness, and the frequency of the fields of interest.
One approach for shielding an image sensor is disclosed in U.S. published patent application number 2009/0115891. This reference discloses a camera module that includes a lens unit comprising at least one lens, an image sensor package including an image sensor chip having an image area where an image is formed in response to light passing through the lens unit, and a housing surrounding the lens unit and the image sensor package. The housing is formed of a conductive material and is electrically connected to the image sensor package via a conductive paste.
Another approach for shielding an image sensor is to use an EMC shield carried by the housing, wherein the EMC shield is coupled to a ground contact on a substrate that carries the housing. In particular, the substrate has a rectangular shape and includes first contacts on a first side and a ground contact on a second side. In this arrangement, a process step is required to connect conductive leads from a focus cell carried by the housing to the first contacts on the first side of the substrate, and a second process step is required to connect a ground conductive lead from the EMC shield to the ground contact on the second side of the substrate. During manufacture, orientation of the image sensor needs to be changed to accommodate the two different process steps.